Various types of projectiles which can be fired at an animal from a distance and which can inject a liquid drug into the animal have been proposed. These projectiles usually are provided with relatively complicated triggering mechanisms for releasing the liquid drugs after impact, and also usually include a considerable amount of additional mechanisms, thereby making the projectiles heavy and cumbersome. In most of these prior-proposed projectiles, the weight of the projectile is so great that it cannot be fired accurately from a distance unless propelled by a cartridge using a chemical explosive. This involves generation of considerable noise, which frightens the animal and causes undesired movement thereof, frequently resulting in a miss. Also, other nearby animals are disturbed and usually run off, removing further opportunity of capturing a desirable specimen.
It is therefore usually desirable to use a noiseless propelling means, such as a blowgun, or the like, which is of simple construction and can be operated merely by lung power.
Examples of previously-proposed projectiles, techniques, and propulsion devices are disclosed in the following prior U.S. patents and the cited publication given herewith:
______________________________________ Hollingsworth, 3,893,866 Crockford et al, 2,854,925 Gregory, 3,042,406 Gesick et al, 3,006,649 Cox, 2,995,373 Palmer, 3,701,533 Van Horn et al 2,617,359 ______________________________________
Brockelman & Kobayshi: "Live Capture of Free-Ranging Primates with a Blowgun", Journal of Wildlife Management, Vol. 35, No. 4, Oct. 1971, pp. 852-855.